Video: Newborn mountain lions a bonus for dying population

The past two years have seen a spike in deaths for mountain lions in Southern California, so two new additions are a warm welcome.

The two wild mountain lion cubs have been captured hissing at a camera trying to sneak a glance at them in their natural habitat.

The adorable fluff balls were born sometime in December, and were found in a well-hidden den in a remote area of the Santa Monica Mountains.

They have been implanted with trackers so their movements can be recorded and tracked.

Despite the increase in deaths, Jeff Sikich, a biologist for Santa Monica Mountains National Recreation Area said in a statement the births show the "quality of the natural habitat is high for such a relatively urbanised area".

"But these kittens have many challenges ahead of them, from evading other mountain lions, to crossing freeways, to dealing with exposure to rat poison."

The pair, one boy and one girl, have been named P-47 and P-46, and were born to mother P-19.

Researchers are hoping their father is P-45, a newly discovered male that has been known to hang back in the western end of the mountains – as P-19's previous cubs were inbred, posing a significant threat to the long-term survival of the species in the Santa Monica Mountains.